As this type of wheel loader, there is a wheel loader which has been disclosed in Patent Literature 1. The wheel loader is provided with wheels, a vehicle body frame with an operator's cab, a working device, etc. The working device is provided with a lift arm which moves in an up/down direction, and a bucket which is attached to a distal end of the lift arm.
As this type of wheel loader, there is a wheel loader having an HST type driving system. The HST type driving system is provided with an HST pump and an HST motor which form a closed circuit, a working machine pump which discharges pressure oil for driving the working device, and a driving wheel system which operates in response to an output from the HST motor.